• Title/Summary/Keyword: Nadir

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Stray Light Analysis of a Compact Imaging Spectrometer for a Microsatellite STSAT-3 (과학기술위성3호 부탑재체 소형영상분광기 미광 해석)

  • Lee, Jin Ah;Lee, Jun Ho
    • Korean Journal of Optics and Photonics
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    • v.23 no.4
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    • pp.167-171
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    • 2012
  • This paper reports on the stray light analysis results of a compact imaging spectrometer (COMIS) for a microsatellite STSAT-3. COMIS images Earth's surface and atmosphere with ground sampling distances of 27 m at the 18~62 spectral bands (0.4 ~ 1.05 ${\mu}m$) for the nadir looking at an altitude of 700 km. COMIS has an imaging telescope and an imaging spectrometer box into which three electronics PCBs are embedded. The telescope images a $27m{\times}28km$ area of Earth surface onto a slit of dimensions $11.8{\mu}m{\times}12.1mm$. This corresponds to a ground sampling distance of 27 m and a swath width of 28 km for nadir looking posture at an altitude of 700 km. Then the optics relays and disperses the slit image onto the detector thereby producing a monochrome image of the entrance slit formed on each row of detector elements. The spectrum of each point in the row is imaged along a detector column. The optical mounts and housing structures are designed in order to prevent stray light from arriving onto the image and so deteriorating the signal to noise ratio (SNR). The stray light analysis, performed by a non-sequential ray tracing software (LightTools) with three dimensional housing and lens modeling, confirms that the ghost and stray light arriving at the detector plane has the relative intensity of ${\sim}10^{-5}$ and furthermore it locates outside the concerned image size i.e. the field of view of the optics.

A Study on the Diurnal Variation of Endorphin in Rat Brain (백서 뇌내 Endorphin의 일주기 변동에 관한 연구)

  • Jung, Chang-Young;Kim, Ki-Won;Cho, Kyu-Park
    • The Korean Journal of Pharmacology
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    • v.20 no.2
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    • pp.35-47
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    • 1984
  • Contents of immunoreactive ${\beta}-endorphin$ and maximum of $^3H-morphine$ binding was measured in the rat midbrain homogenates from different subgroups at 24 hour interval over 24 hours. Animals were adapted to the light-dark cycle(L : D, 12: 12) or constant darkness (D : D, 12 : 12) for 3 weeks. After the adaptation, 0.5ml of physiologic saline or drug was administered twice a day for 2 weeks. A highly significant circadian rhythm with the peak$(94.8{\pm}7.7\;fmole/mg\;protein)$ at 06:00 and the nadir $(27.6{\pm}2.4\;fmole/mg\;protein)$ at 18:00 was observed in constant of group. Constant dark or treatment of reserpine, pargyline, imipramine, amphetamine and chlorpromazine modified the diurnal rhythm in the time of peak and nadir, shape, phase amplitude and 24 hour mean of ${\beta}-endorphin$ contents. Opiate receptor binding by $^3H-morphine$ also showed highly significant diurnal change in control and constant dark adapted rats. Statistical analysis by one-way analysis of variance and two-way analysis of variance indicates that the·re are highly significant differences between the diurnal change of ${\beta}-endorphin$ in control and those constant dark adapted and drug treated groups. However diurnal change of Maximum $^3H-morphine$ binding is closely related to the change of ${\beta}-endorphin$ contents. The results are interpreted with regard to the circadian rhythm of beta-endorphin contents, its modification by psychoactive drugs and possible mechanism of diurnal change of opiate receptor in brain.

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A Study on the Circadian Rhythm of Opiate Receptor in Rat Brain (백서 뇌내 Opiate 수용체의 일주기 변동에 대한 연구)

  • Lee, Moo-Suck;Kim, Ki-Won;Cho, Kyu-Park
    • The Korean Journal of Pharmacology
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    • v.20 no.2
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    • pp.23-34
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    • 1984
  • To investigate diurnal variations of opiate receptor binding and its modification by experimental condition or treatment of various centrally-acting drugs, the amount of maximum $^3H-morphine$ binding in rat midbrain homogenates was measured at 4 hour intervals for 24 hours. Animals were conditioned under the controlled L : D, 12 : 12 cycle or D: D, 12 : 12 cycle, for 3 weeks and treated with 0.5 ml of physiological saline or drugs for 2 weeks. A highly significant diurnal rhythm with peak at 22 hour of early dark phase with an amplitude$(0.68{\pm}0.06\;pmole/mg\;protein)$ of +51.1% and nadir $(0.33{\pm}0.03\;mole/mg\;prtein)$ at 18 hour of late light phase with an amplitude of -26.6% was found in control group. 24 tour mean of $^3H-morphine$ binding was $0.45{\pm}0.03\;pmole/mg$ protein respectively. Constant dark adaptation or treatment of reserpine, pargyline, imipramine, amphetamine and chlorpromazine modified the diurnal rhythm in the time of peak and nadir binding shape, phase, amplitude of the diurnal curve and 24 hour mean of $^3H-morphine$ binding. However, Kd values were not changed in all experimental groups : Statistical analysis at times of least and great binding indicates that the differences in $^3H-morphine$ binding were due to changes not in the affinity, but in the number of binding sites. The results are interpreted with regard to the diurnal rhythm of opiate receptor finding. The modes of action of psychoactive drugs are closely related to postulated changes of receptor sensitivity in neuropharmacological aspects.

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KOMPSAT-2 Direct Sensor Modeling and Geometric Accuracy Analysis (다목적실용위성2호 센서모델링 및 기하정확도 분석)

  • Seo, Doo-Chun;Kim, Moon-Gyu;Lee, Dong-Han;Song, Jeong-Heon;Park, Su-Young;Lim, Hyo-Suk;An, Gi-Won;Lee, Hyo-Seong
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.149-152
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    • 2007
  • The horizontal geo-location accuracy of KOMPSAT-2, without GCPs (Ground Control Points) is 80 meters CE90 for monoscopic image of up to 26 degrees off-nadir angle, after processing including POD (Precise Orbit Determination), PAD(Precise Attitude Determination) and AOCS (Attitude and Orbit Control Subsystem) sensor calibration. In case of multiple stereo images, without GCPs, the vertical geometric accuracy is less than 22.4 meters LE 90 and the horizontal geometric accuracy is less than 25.4 meters. There are two types of sensor model for KOMPSAT-2, direct sensor model and Rational Function Model (RFM). In general, a sensor model relates object coordinates to image coordinates The major objective of this investigation is to check and verify the geometrical performance when initial KOMPSAT-2 images are employed and briefly introduce the sensor model of KOMPSAT-2.

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Analysis on the Effects of Interference from HAPS ground stations to P-MP FWA System (HAPS 지상국에서 P-MP FWA 시스템으로의 간섭 영향 분석)

  • Ham, Hyoung-Il;Choi, Mun-Hwan;Kang, Young-Heung
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.157-162
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    • 2005
  • In this paper, we have analyzed the effects of interference from HAPS ground stations to P-MP FWA base station and to P-MP FWA terminal station using more detail parameters such as a new interference model, a realistic HAPS scenario, practical antenna patterns for both the HAPS system and FWA systems. The analysis results show that, in the case of interference from HAPS GSs into a P-MP BS, compatibility of the two systems can be obtained by using a sectored BS antenna with the boresight directed away from the nadir However, in the case of interference from HAPS GSs into a P-MP TS, the two systems cannot operate effectively in the same band unless the separation distance is guranteed and/or some form of interference mitigation technique is employed such as dynamic channel allocation.

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Subacute Inflammatory Demyelinating Polyneuropathy Combined with Optic Neuritis (시신경염이 동반된 아급성염증탈수초다발신경병)

  • Kim, Sieun;Park, Kang Min;Park, Jinse;Ha, Sam Yeol;Kim, Sung Eun;Kim, Jong Kuk;Shin, Kyong Jin
    • Annals of Clinical Neurophysiology
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    • v.15 no.1
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    • pp.13-18
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    • 2013
  • It was sometimes difficult to differentiate between acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) and subacute inflammatory demyelinating polyneuropathy (SIDP). The CNS involvement of these polyneuropathies has rarely reported in the literature. We present the case of a 42-year-old man who developed rapidly developing inflammatory demyelinating polyneuropathy followed by right optic neuritis. This case showed progressive motor weakness and sensory dysfunction with time to nadir at 8 weeks, demyelination in nerve conduction study, no other etiology of neuropathy, no relapse during follow-up of 18 months, good response to steroid and complete recovery which favor SIDP more than A-CIDP. We experienced the case of SIDP associated with optic neuritis.

Effect of G-CSF on Myelosuppression and Antitumor Effect of DA-125, a Novel Adfiamycin Derivative (새로운 아드리아마이신유도체 DA-125의 초혈기독성과 항암효과에 미치는 G-CSF의 영향)

  • 안병욱;류병권;이상득;김원배;양중익
    • Biomolecules & Therapeutics
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    • v.5 no.2
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    • pp.110-116
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    • 1997
  • The present study was designed to evaluate the effects of a recombinant human granulocyte-colony stimulating factor (G-CSF) on leukopenia and tumor growth in mice treated with DA-125, an adri-amycin (ADM) derivative. In normal mice, single intravenous injection of DA-125 produced transient leukopenia accompanied with weight loss and splenic atrophy in a dose-related manner. However, subcutane-ous administration of G-CSF (5$\mu$g/head) for 5 consecutive days after DA-125 resulted in a significantly elevated nadir of leukocyte counts and facilitation of recovery from the leukopenia. To investigate the effect of G-CSF on antitumor effects of DA-125, ADM (12 mg/kg) or DA-125 (40 mg/kg) was administered to Colon-26 murine adenocarcinoma-bearing Balb/c mice with G-CSF. Regardless of treatment with G-CSF, DA-125 and ADM markedly retarded the growth of implanted tumor, though they failed to increase mean survival time of tumor-bearing mice. These results suggest that G-CSF is able to not only ameliorate, but reconstitute DA-125-induced myelosuppression without affecting its antitumor potential.

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Study on effective band of advanced microwave scanning radiometer (AMSR) for observing first year sea ice in the Okhotsk Sea by airborne microwave radiometer (AMR)

  • Nakayama, Masashige;Nishio, Fumihiko;Tanikawa, Tomonori;Cho, Kohei;Shimoda, Haruhisa
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.456-461
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    • 1999
  • It is very important for monitoring the interannual variability of sea ice extents in the Okhotsk Sea because the global warming has firstly appeared around the Okhotsk Sea, locating around the southernmost region of sea ice cover in the Northern Hemisphere. In order to develop the sea ice concentration algorithm by microwave sensors onboard satellite, electromagnetic properties of sea ice in the Okhotsk Sea, therefore, were observed by airborne microwave radiometer (AMR), which has the same frequencies as AMSR (Advanced Microwave Scanning Radiometer), ADEOS-II, launching on November, 2000. On this study, it is discussed how to make the image of AMR-EFOV and the video image with nadir angle under flight at the same time, and superimpose the brightness temperature data by AMR-EFOV on the video mosaiced images. For comparing SPOT image, it is clearly that the variation of brightness temperature is small in 89GHz V-pol without the sea ice types and increase at the lower frequency-band.

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Inertial Control of a DFIG-based Wind Power Plant using the Maximum Rate of Change of Frequency and the Frequency Deviation

  • Lee, Hyewon;Kim, Jinho;Hur, Don;Kang, Yong Cheol
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.496-503
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    • 2015
  • In order to let a wind generator (WG) support the frequency control of a power system, a conventional inertial control algorithm using the rate of change of frequency (ROCOF) and frequency deviation loops was suggested. The ROCOF loop is prevailing at the initial stage of the disturbance, but the contribution becomes smaller as time goes on. Moreover, its contribution becomes negative after the frequency rebound. This paper proposes an inertial control algorithm of a wind power plant (WPP) using the maximum ROCOF and frequency deviation loops. The proposed algorithm replaces the ROCOF loop in the conventional inertial control algorithm with the maximum ROCOF loop to retain the maximum value of the ROCOF and eliminate the negative effect after the frequency rebound. The algorithm releases more kinetic energy both before and after the frequency rebound and increases the frequency nadir more than the conventional ROCOF and frequency loops. The performance of the algorithm was investigated under various wind conditions in a model system, which includes a doubly-fed induction generator-based WPP using an EMTP-RV simulator. The results indicate that the algorithm can improve the frequency drop for a disturbance by releasing more kinetic energy.

Independent Component Analysis Based MIMO Transceiver With Improved Performance In Time Varying Wireless Channels

  • Uddin, Zahoor;Ahmad, Ayaz;Iqbal, Muhammad;Shah, Nadir
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.7
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    • pp.2435-2453
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    • 2015
  • Independent component analysis (ICA) is a signal processing technique used for un-mixing of the mixed recorded signals. In wireless communication, ICA is mainly used in multiple input multiple output (MIMO) systems. Most of the existing work regarding the ICA applications in MIMO systems assumed static or quasi static wireless channels. Performance of the ICA algorithms degrades in case of time varying wireless channels and is further degraded if the data block lengths are reduced to get the quasi stationarity. In this paper, we propose an ICA based MIMO transceiver that performs well in time varying wireless channels, even for smaller data blocks. Simulation is performed over quadrature amplitude modulated (QAM) signals. Results show that the proposed transceiver system outperforms the existing MIMO system utilizing the FastICA and the OBAICA algorithms in both the transceiver systems for time varying wireless channels. Performance improvement is observed for different data blocks lengths and signal to noise ratios (SNRs).